Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see
Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Restrictions for EIGRP Route Tag Enhancements

Default route tags are not supported in EIGRP autonomous system configurations.

Route tags will not be displayed in dotted-decimal format if the
route-tag notation global configuration command is not enabled on the device.

Information About EIGRP Route Tag Enhancements

EIGRP Route Tag Enhancements Overview

A route tag is a 32-bit value attached to routes. Route tags are used to filter routes and apply administrative policies, such as redistribution and route summarization, to tagged routes. You can tag routes within a route map by using the
set tag command. You can match tagged routes and apply administrative policies to tagged routes within a route map by using the
match tag or
match tag list command. The
match tag list command is used to match a list of route tags.

Prior to the EIGRP Route Tag Enhancements feature, EIGRP routes could only be tagged using plain decimals (range: 1 to 4294967295). This feature enables users to specify and display route tag values as dotted decimals (range: 0.0.0.0 to 255.255.255.255), similar to the format used by IPv4 addresses. This enhancement is intended to simplify the use of route tags as users can now filter routes by using the route tag wildcard mask.

This feature also allows you to configure a default route tag for all internal EIGRP routes without using route maps. Use the
eigrp default-route-tag command in address family configuration mode to configure a default route tag for internal EIGRP routes.

Use the
list-name argument to display information about a specific route tag list.

Matching a Route Tag List

Route tag lists are used in route maps to match routes based on conditions specified in the route tag lists. Multiple route tag and mask pair sequences can be configured to permit or deny any condition for a list of route tags.

Note

You can match either a route tag or a route tag list within a single route map sequence.

Perform this task to match routes based on conditions specified in the route tag list.
SUMMARY STEPS

Example: Enabling Dotted-Decimal Notation for Route Tags

The following example shows how to enable the display of route tags in dotted-decimal format by using the
route-tag notation command. If you do not configure the
route-tag notation command, route tags will be displayed as plain decimals in
show commands even if the route tags were configured as dotted decimals. When you configure the
route-tag notation command, route tags will be displayed as dotted decimals even if the route tags were configured as plain decimals.

Example: Configuring a Route Tag List

The following example shows how to configure a route tag list named TAG with various criteria for filtering routes. Route maps will use this list to match routes based on the criteria specified in the list. Route tag lists can accept route tags and wild card masks.

Example: Matching a Route Tag List

The following example shows how to use a route map to filter routes that match a specific route tag list. A single list can have multiple match criteria. All criteria must match before the route can be filtered. This example shows how to configure a route tag list named List1 in a route map and use the
match tag list command to filter routes that match the criteria listed in the route tag list.

Additional References

Related Documents

Technical Assistance

Description

Link

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Feature Information for EIGRP
Route Tag Enhancements

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/​go/​cfn. An account on Cisco.com is not required.